In known methods of building using hollow bricks, it is conventional to use a trowel to place the mortar on to the bricks. The trowel used is that which normally is used for placing mortar on to solid bricks. Unless the trowel is used with considerable skill, a substantial amount of the mortar will fall between the walls of the hollow brick. Additionally, to place the correct amount of mortar onto the walls of the brick is a task of some difficulty which is inordinately time consuming.